1. Field of the Invention
The present invention relates to a luminous element, and more particularly, to a luminous element for a backlight unit with a plurality of luminous chips mounted on a substrate.
2. Discussion of the Background
In general, the application range of a liquid crystal displays (LCD) has extended because of its lightweight, thin, low-power drive, full color and high resolution characteristics. A liquid crystal display has been currently used in a computer, notebook computer, PDA, telephone, TV, audio/video device or the like. In such a liquid crystal display, transmitted amount of light is controlled in accordance with image signals applied to a number of control switches arrayed in a matrix form and then a desired image is displayed on a liquid crystal display panel.
Since the liquid crystal display cannot emit light by itself, it requires a light source such as a backlight unit. Such a backlight for a liquid crystal display there are two kinds of illuminating type which are edge light and direct light types depending on a position of a light source.
The edge light type is a type in which a light source is mounted at an edge of a liquid crystal display panel such that light produced from the light source is emitted to the liquid crystal display panel through a light guide plate positioned below the liquid crystal display panel. The edge light type has superior uniformity of light, is advantageous in manufacturing thin liquid crystal displays, and is generally used to supply light in medium- and small-sized liquid crystal display panels. Meanwhile, the direct light type is a type in which a plurality of light sources are positioned below a liquid crystal display panel such that light is emitted directly to an entire surface of the liquid crystal display panel. The direct light type can secure high luminance and is generally used to supply light in medium- and large-sized liquid crystal display panels.
At this time, an electroluminescent lamp (EL), a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL) or the like is used as a light source of the backlight unit.
Here, in an edge light type backlight unit using light emitting diodes according to a prior art, a plurality of side luminous elements are separately manufactured and mounted to a substrate such as a flexible printed circuit board (FPCB), FR-4 or metal core printed circuit board (MCPCB).
However, in the aforementioned conventional structure, an assembling process is complicated and difficult, and the processing time and cost are required to mount the separately manufactured luminous elements on a substrate. That is, since a substrate having luminous chips mounted thereon and the luminous element including the luminous chips mounted on the substrate should be arranged on a separately prepared circuit board, the cost caused from the addition of the circuit board is increased. Further, the additional circuit board requires a space for positioning the luminous elements. Accordingly, there is a problem in that the entire size of a backlight unit is increased.